Prefabricated concrete structure

ABSTRACT

Each supporting column includes vertically aligned prefabricated concrete shafts, and steel members embedded in each shaft project downward into a pocket in the upper portion of the next lower shaft, the pocket being filled with a concrete mix into which the projecting steel members of the superimposed shaft are inserted before the mix has set. Angle irons welded to these steel members have horizontal flanges substantially flush with the lower end of the corresponding column shaft, and the flanges are secured to the upper ends of anchor rods embedded in the underlying shaft outside its said pocket. Integral with each column shaft are four horizontal brackets extending at a common level with an angle of 90* between each pair of adjacent brackets, and a prefabricated concrete girder extends horizontally from each bracket of each column to an opposing bracket of a remote column, each end portion of the girder resting upon and being interlocked with a shelf on the adjacent bracket. The opposite sides of the girders and brackets have ledges on which rest the adjacent marginal portions of prefabricated concrete floor slabs, these marginal portions interlocking with the ledges. Special means are provided for centering, leveling and aligning the interlocking parts.

United States Patent "1191 Kessler 1 Mar. 27, 1973 PREFABRICATED CONCRETE Primary ExaminerFrank L. Abbott STRUCTURE Assistant Examiner--James L. Ridgill, Jr [76] Inventor: Samuel J. Kessler, 2500 Johnson Attorney cyms HapgQod et Avenue, R1verdaIe, N.Y. 10463 [57] ABSTRACT [22] Flled' 1971 Each supporting column includes vertically aligned [21] Appl. No.: 193,083 prefabricated concrete shafts, and steel members embedded in each shaft project downward into a pocket 52 US. Cl. .,.52/252, 52/259,52/260, the 0f the next l f f the 52/283 52/295 52/583 52/587, 52/721 pocket being filled with a concrete mix nto which the 51 Int. Cl. ..E04b 1/30, E04b 1/54 Pmjecfing Steel members the superlmposed Shaft 58 Field of Search ..52/250 252, 263, are insmed before the mix has Angle irons 52/259462, 301, 283, 6 295 8 welded to these steel members have'horizontal flanges 5 5 5 7 720 721 72 substantially flushwith the lower end Of the C01- responding column shaft, and the flanges aresecured 5 References Cited to the upper ends of anchor rods embedded in the unv h v derlying shaft outside its said pocket. Integral with UNITED STATES PATENTS each column shaft are four horizontal brackets exs44,974 2/1907 Thorn 52 721 tending at a with an angle of 900 1,071,523 8/1913 Lally ..52 301 betweel} each l brackets and 3 1,796,048 3/1931 Robinson ..52/60l prefabflcated Concrete glrder extends horizontally 2,724,261 11 1955 Rensaa.....-. ..52 283 from each bracket of each column to an opposing 3,110,982 3 esin ger 52/301 bracket of a remote column, each end portion of the 3,354,593 11/1967 Zukas resting upon and being interlocked a shelf 3,374,592 3/1968 F on the adjacent bracket. The opposite sides of the gir- 3,562,978 2/ 1971 Ah-Oglu ..52/26 3 FOREIGN PATENTS OR APPLICATIONS ders and brackets have ledges on which rest the ad- I jacent marginal portions of prefabricated concrete floor slabs, these marginal portions interlocking with the ledges. Special means are provided for centering, leveling and aligning the interlocking parts.

9 Claims, 9 Drawing Figures PATENTEDHARZYISB 3 5 SHEET 20F 4 INVENTOR. J/wua J frz-sszm BY 2W; I

PREFABRICATED CONCRETE STRUCTURE This invention -relates to reinforced concrete structures and more particularly to a novel structure of this type which can be erected at relatively low cost from prefabricated sections while conforming with accepted design practices.

Objects of the present invention are to provide a prefabricated structure as indicated above which can be erected with less labor than heretofore required for such structures and in which all sections, when erected and interlocked with abutting members, are self-centering, self-aligning and self-leveling.

A structure made according to the invention comprises supporting columns which may be located in a conventional pattern for buildings such as apartment houses, office buildings, etc. Each column includes a plurality of vertically aligned prefabricated concrete shafts, each shaft having steel members embedded in its lower portion, and projecting downward into a pocket in the next lower shaft. In erecting the column, the pocket of each shaft is filled with concrete mix, and the next upper shaft is lowered until it rests upon the top of the lower shaft with the projecting steel members inserted in the mix before it sets; and thereafter the upper shaft is adjusted to its final position and secured by connecting anchor bolts in the lower shaft to angle irons welded to the steel members of the upper shaft, leveling plates being preferably provided between the angle irons and the top of the lower shaft.

Each vertical shaft of each column has integral concrete brackets extending horizontally, and each bracket has a shelf protruding from its outer end below the top of the bracket and also has an upwardly extending tongue on this end shaft, the tongue and the outer end of the bracket forming a groove extending transversely of the bracket. Prefabricated concrete girders are supported by the brackets to form a framework for supporting prefabricated concrete floor slabs. Each girder extends horizontally from a bracket of one column to an opposing bracket of a remote column, the opposite end portions of the girder having downwardly extending tongues located in the aforementioned grooves of the opposing brackets and also having transverse grooves receiving the upwardly extending tongues of the opposing brackets. The girders and brackets manner, with effective interlocking between abutting parts and with such reinforcements as may be required to conform with accepted design practices.

These and other features of the invention may be better understood from the following description with reference to the accompanying drawings illustrating a preferred embodiment of the new structure. In the drawings:

7 FIG. l is a floor plan view of part of the structure;

FIG. 2 is an enlarged side elevational view partly in section, of one of the supporting columns shown in FIG. 1, with parts broken away;

FIG. 3 is an enlarged vertical sectional view of part of the column shown in FIG. 2;

FIG. 4 is a horizontal sectional view on line 4-4 in FIG. 3; i

FIG. 5 is an enlarged elevational view, partly in section, of one of the steel members and angle irons shown in FIGS. 3 and 4; 7

FIG. 6 is an enlarged sectional view on line 66 in FIG. 2;

FIG. 7 is an enlarged sectional view on line 7-7 in 7 FIG. 1, with parts broken away;

have ledges protruding from their opposite sides below the tops thereof and also have tongues protruding upwardly from the ledges, the ledge tongues partly defining grooves extending along the ledges. The floor slabs have marginal portions resting on these ledges, the lower surfaces of these marginal portions having grooves receiving the ledge tongues and also having downwardly extending protrusions received in the ledge grooves.

Preferably, the opposite end portions of each girder are provided in their upper surfaces with longitudinal grooves, and the corresponding opposed column brackets are grooved in their upper surfaces to form extensions of the girder grooves. In erecting the structure, a steel rod-is inserted in each girder groove and its extension in the adjacent bracket so as to effect proper alignment of these parts, after which the groove is filled with concrete to embed the aligning rod.

Thus, the new structure can be erected from prefabricated concrete-parts in a relatively simple FIG. 8 is an enlarged sectional view on line 8-8 in FIG. 1, with parts broken away, and

FIG. 9 is an enlarged sectional view of parts of a modified form of the new structure.

The structure as shown in FIG. 1 comprises a group of prefabricated concrete supporting columns arranged in a suitable pattern, four of these columns being shown at C. At each floor level of the structure, the columns C are each provided with integral concrete brackets C1, C2, C3 and C4 extending horizontally from the column with an angle of between each pair of adjacent brackets. These brackets of the columns support prefabricated concrete girders each of which extends horizontally from a bracket of one column to an opposing bracket of a remote column. These girders include two girders G1 extending in one direction between op posing brackets Cl and C3 of respective pairs of columns, and they also include two girders G2 extending at right angles to the girders GI, each of the parallel girders G2 extending from a bracket C2 of one column to an opposing bracket C4 of another column.

Accordingly, the girders G1 and G2, together with their supporting brackets, form a four-sided framework for supporting prefabricated floor slabs S1 and S2. In similar fashion, other such girders (some of which are shown at G3, G4 and G5) form similar frameworks with the other brackets of column C and with the brackets of other columns (not shown), it being understood that a bracket is eliminated wherever it would otherwise extend into an exterior wall (not shown) of the building structure.

The floor slabs S1 and S2 span the girders G1, and each of the slabs S1 has one side abutting a girder G2, the intermediate slab S2 having its opposite sides abutting adjacent sides of the two slabs S1, respectively. Additional floor slabs S3 and S4 are similarly supported by the other four-sided frameworks similar to that provided by the girders G1 and G2 and their supporting brackets.

Each of the columns C is constructed as illustrated in FIG. 2. As there shown, the column C comprises a plurality of vertically aligned prefabricated concrete shafts which are identical to each other, two of these-shafts being shown at 10 and 100. Each of these shafts has a pocket 11 in its upper end and is provided with steel members 12 embedded in its lower portion. The members 12 protrude from the lower end of the shaft, as shown at 12a, and extend into the pocket ll-of the next lower shaft. The lowermost shaft 10 has its steel members l2 projecting at 12a into a pocket 11a in a footing F I As shown in FIGS. 3-5, each column shaft 10 has four anchor bolts 14 embedded in its upper portion outside the pocket 11. Angle irons 15 are welded to the steel members 12 of the next higher column shaft 10a. The latter is provided with four of the steel members 12 (FIG. 4), one of the angle irons 15 being welded to one pair of these members and a second angle iron being welded to the other pair. The anchor bolts 14 project upwardly from the lower shaft 10 and through the horizontal flanges of the angle irons l5. Fastener means, such as nuts 16, are threaded on the upper ends of the anchor bolts and tightened down against these angle iron flanges to effect a secure connection between the column shafts 10 and 10a.

In assembling the two column shafts 10-1011, the pocket 11 of the lower shaft 10 is filled with concrete mix after leveling plates 18 (FIG. have been set in the finished floor in locations where they will engage the horizontal flanges of the angle irons 15. Each leveling plate 18 may be set to its proper height by adjustment of an underlying nut 19 threaded on the anchor bolt 14 which extends through the leveling plate,'as shown in FIG. 5. Before the concrete mix in the pocket 11 is set, the upper shaft a is lowered until the horizontal flanges of its angle irons rest upon the corresponding leveling plates 18, at which point the downwardly projecting portions 12a of the steel members in shaft 10a will be located in the pocket 11 of the lower shaft, with the lower ends of these members closely spaced from the bottom of the pocket. The nuts 16 are then applied to and tightened down on the threaded upper ends of the anchor bolts 14 where they project through the angle irons 15. The permit access of the projecting upper portions of the anchor rods, the upper shaft 10a is provided with corner recesses 17, and these recesses are framed and grouted with 1 inch slump, quality concrete immediately after the floor is completed.

The upper shaft 10a is provided in its lower end portion with passages 20 (FIGS. 4 and 5), each of these passages opening through one side of the shaft and communicating at its inner end with the pocket 11 in the lower shaft 10. Thus, as the steel projections 12a of the upper shaft enter the concrete mix in the pocket 11 of the lower shaft, excess concrete will be forced out through the passages 20.

The outer end of each horizontal bracket C1,C2, C3 and C4 is provided with a shelf 22 located between the top and bottom of the bracket (FIG. 2). A tongue 23 projects upwardly from each shelf and forms a groove 24 extending transversely of the bracket between tongue 23 and the cut-back end of the bracket. Each end of each girder G is provided at its upper portion with a protrusion 25 adapted to rest upon the shelf 22 of the abutting bracket (FIG. 2), whereby the bracket groove 24 receives a downwardly projecting tongue 26 of the protrusion 25, and the bracket tongue 23 is received in a groove of the protrusion adjacent its tongue 26. Thus, the girders G are firmly interlocked at their ends with the abutting ends of the brackets. Steel reinforcing members 27 are embedded in the girders G at the regions of their protrusions 25 and in the brackets at the regions of their shelves 22.

As shown in FIGS. 2 and 6, the girders G are formed in the upper surfaces of their end portions with longitudinal grooves 29, and the brackets are formed at their end portions with similar grooves 30 in theirupper surfaces. Similar grooves 290 and 30a are formed in the lower surfaces of the girders and the brackets, respectively. When each girder is properly aligned withthe brackets abutting its ends, its longitudinal grooves 29 and 290 are in alignmentwith the respective grooves 30 and 30a of the brackets. This alignment is preserved by inserting a rod 31 in each pair of aligned grooves, the lower rods 31 being retained in their respective grooves in any suitable manner, as by forcing plugs (not shown) into the grooves. The grooves 29-30 and 29a-30a are subsequently filled with concrete to embed the rods.

Each girder G has a ledge 33 extending along each side throughout the entire length of the girder, these ledges being located between the upper and lower surfaces of the girder at an elevation to receive the slab S1 (FIG. 6). Each ledge 33 has an upwardly extending tongue 34 forming a groove 35 extending from end to end of the girder. Likewise, each of the column brackets C1, C2, C3 and C4 has similar ledges 36 extending along its opposite sides (FIG. 8), these ledges having tongues 34 and grooves similar to and aligned with the respective tongues 34 and grooves 35 of the. corresponding girder G.

The ends of the intermediate floor slab S2 (FIG. 1) rest upon adjacent ledges 33 (FIG. 6) of the parallel girders G1, and the ends of the two floor slabs S1 rest partly upon these ledges and partly upon the bracket ledges 36 (FIG. 8) aligned therewith. As shown in FIGS. 6 and 8, the lower surfaces of slabs S are grooved to receive the ledge tongues 34, these grooves forming tongues 37 fitting into the ledge grooves 35.

As shown in FIG. 7, each girder G2 is similar in cross-section to girders G1 except that its vertical dimension is less than that of girders G1, its ledges 33a being shown as having one-half the height of ledges 33. Floor slabs S1 are undercut along their opposite sides to form lateral protrusions 38 which are one-half the slab thickness. The protrusion 38 adjacent girder G2 rests upon ledge 33a and is grooved in its lower surface to receive the ledge tongue 340, this groove forming a tongue 37a fitting into the ledge groove. The other protrusion 38 of each slab S1 rests upon a ledge 39 on the adjacent side of intermediate slab S2, each ledge 39 interlocking with the overlying protrusion in the same manner as the girder ledge 33a.

Accordingly, the floor slabs S1 and S2 are interlocked with each .other and with the fourgirders G1 and G2 forming the framework for these slabs.

By the use of the rods 31 in their respective aligned grooves, as previously described, I provide a construction continuity where a rigid frame structure is desired", but it will be understood that these rods may be omitted when such continuity is not essential or when a flexible frame structure is desired. Also, although the rods 31 and their grooves are shown as extending only longitudinally of the girders to align them with the corresponding column brackets (FIGS. 2 and 6), it will be understood that a similar arrangement may be applied transversely of the girders so that each rod extends from a surface groove of a floor slab into an aligned groove in a girder or column bracket. Of course, steel members other than those previously described may be embedded in the prefabricated concrete parts at such locations where reinforcement may be desired. Also, leveling plates may be employed at other locations than in the columns C, such as on the bottoms of the girder ledge grooves 35 (FIG. 6).

Referring to FIG. 9, the column bracket C3 is shown with a steel angle member 41 embedded therein and extending lengthwise of the bracket into its end shelf 22, the upper edge 41a of the member 41 being located above the bottom of shelf groove 24. The protrusion 25 of girder G5 has a steel angle 42 embedded therein and I extending transversely of the girder. The lower edge of angle 42 is flush with the bottom of tongue 26 and rests upon the upper edge 41a of member 41'. Additional steel members 41 may be spaced along the end shelf 22 so as to support the steel angle 42 at intervals along its length.

It will be apparent that the level of girder G5, where it is supported by bracket C3, is determined by the vertical spacing of the upper edge 41a of member 41 from the bottom of shelf groove 24. This spacing is such as to make the top of girder G5 flush with the top of column bracket C3. Moreover, it provides a clearance between the entire top of end shelf 22 and the overlying bottom members embedded'in' the lower portion'of each column shaft and having extensions protruding downward into said pocket of the next lower vertically aligned shaft, concrete fill occupying each said pocket of the girder protrusion 25, for a purpose which will now be explained.

As also appears from FIG. 9, the opposing ends of girder G5 and bracket C3 are spaced from each other, thereby forming a continuous passage 43 extending from their upper surfaces to their lower surfaces by way of the vertical clearance between the top of shelf 22 and the bottom of protrusion 25. This passage is vacuum cleaned and then filled under pressure with a cement mixture 43a, after temporarily blocking the sides of the passage. The bottom of this passage is also blocked, as shown at 44, to prevent escape of the cement from the passage 43.

The arrangement described above in connection with FIG. 9 provides self-leveling of the various girders in addition to a readily applied joint 43a between each column bracket and the opposing girder end. It will be understood that this arrangement may also be used for leveling the floor slabs where they rest upon the lateral shelves of the girders and column brackets, and for providing similar joints between these slabs and the opposing lateral surfaces of the girders or brackets. In this way, the structure may be readily erected with automatic leveling of each floor in its entirety.

If desired for rigid continuity between adjacent precast concrete members, each member may have longitudinal reinforcing elements 46 of steel embedded therein near its upper and lower surfaces, as shown in FIG. 9, adjacent ends of these elements being welded to an intervening steel section 47 extending transversely of the elements 46. To enable such welding, the concrete members (C3 and G5 in FIG. 9 ).are recessed as shown at 48, these recesses being filled under pressure with concrete after the welding is completed.

and in which the corresponding extensions are embedded, angle irons welded to said steel members of each column shaft and having horizontal flanges through which said anchor rods extend upwardly from the next lower vertically aligned shaft, fastening means securing the upper ends of the anchor rods to the corresponding horizontal flanges of said angle irons, horizontal concrete brackets integral with each said column shaft, each bracket having a shelf protruding from its outer end below the top of the bracket and also having an upwardly extending tongue on said end shelf, said tongue and the outer end of each bracket forming agroove extending transversely of the bracket, a prefabricated concrete girder extending horizontally from each bracket of each column to an opposing bracket of -a remote column, the opposite end portions of each girder having downwardly extending tongues located in said grooves of the corresponding opposing brackets and also having transverse grooves receiving said upwardly extending tongues of the corresponding opposing brackets, said girders and brackets having ledges protruding from the opposite sides thereof below the tops thereof and also having tongues protruding upwardly from said ledges, said ledge tongues partly defining grooves extending along said ledges at opposite sides of the girders and brackets, and prefabricated concrete floor slabs having marginal portions resting on said ledges, the lower surfaces of said marginal portions having grooves receiving said ledge tongues and also having downwardly extending protrusions received in said ledge grooves.

2. The combination according to claim 1, comprising also leveling plates interposed between the upper end also steel reinforcement members embedded in said opposite end portions of the girders.

6. The combination according to claim 1, in which the opposite end portions of each girder are provided with longitudinal grooves in the upper surface of the girder, the upper surfaces of said brackets being grooved to form extensions of said longitudinal grooves in the adjacent end portions of the girders, the combination also comprising a horizontal steel rod located in each of said longitudinal grooves and said extension thereof, and concrete filling said grooves and extensions to embed said horizontal rods therein.

7. The combination according to claim 1, in which the opposite end portions of each girder are provided with longitudinal grooves in the lower surface of the girder, the lower surfaces of said brackets being gi'oovd to form extensions of said lon'gitudinal'grooves in the, adjacent end portions of the girders, the combination comprising also a horizontal steel rod located in each of-said longitlidinal grooves and said extension thereof, and concrete filling said grooves and extensions to embed said horizontal rods therein.

8. The combination according to claim l,'compri'sing also a first steel member embedded in at least one of tending from the top of said overlying part to the bottom of said shelf or ledge, the combination comprising also cement filling said passage to form a joint. 

1. In a prefabricated, reinforced concrete structure, the combination of supporting columns each including a plurality of vertically aligned prefabricated concrete shafts, each of said shafts having a pocket in the upper end thereof, anchor rods embedded in the upper portion of each column shaft outside said pocket and protruding above said upper end of the shaft, steel members embedded in the lower portion of each column shaft and having extensions protruding downward into said pocket of the next lower vertically aligned shaft, concrete fill occupying each said pocket and in which the corresponding extensions are embedded, angle irons welded to said steel members of each column shaft and having horizontal flanges through which said anchor rods extend upwardly from the next lower vertically aligned shaft, fastening means securing the upper ends of the anchor rods to The corresponding horizontal flanges of said angle irons, horizontal concrete brackets integral with each said column shaft, each bracket having a shelf protruding from its outer end below the top of the bracket and also having an upwardly extending tongue on said end shelf, said tongue and the outer end of each bracket forming a groove extending transversely of the bracket, a prefabricated concrete girder extending horizontally from each bracket of each column to an opposing bracket of a remote column, the opposite end portions of each girder having downwardly extending tongues located in said grooves of the corresponding opposing brackets and also having transverse grooves receiving said upwardly extending tongues of the corresponding opposing brackets, said girders and brackets having ledges protruding from the opposite sides thereof below the tops thereof and also having tongues protruding upwardly from said ledges, said ledge tongues partly defining grooves extending along said ledges at opposite sides of the girders and brackets, and prefabricated concrete floor slabs having marginal portions resting on said ledges, the lower surfaces of said marginal portions having grooves receiving said ledge tongues and also having downwardly extending protrusions received in said ledge grooves.
 2. The combination according to claim 1, comprising also leveling plates interposed between the upper end of each column shaft and said horizontal flanges of the next upper vertically aligned shaft.
 3. The combination according to claim 1, in which the lower portion of each column shaft has a passage opening through one side of the shaft and communicating with said pocket of the next lower vertically aligned shaft.
 4. The combination according to claim 1, comprising also steel reinforcement members embedded in said brackets and extending into said end shelves thereof.
 5. The combination according to claim 1, comprising also steel reinforcement members embedded in said opposite end portions of the girders.
 6. The combination according to claim 1, in which the opposite end portions of each girder are provided with longitudinal grooves in the upper surface of the girder, the upper surfaces of said brackets being grooved to form extensions of said longitudinal grooves in the adjacent end portions of the girders, the combination also comprising a horizontal steel rod located in each of said longitudinal grooves and said extension thereof, and concrete filling said grooves and extensions to embed said horizontal rods therein.
 7. The combination according to claim 1, in which the opposite end portions of each girder are provided with longitudinal grooves in the lower surface of the girder, the lower surfaces of said brackets being grooved to form extensions of said longitudinal grooves in the adjacent end portions of the girders, the combination comprising also a horizontal steel rod located in each of said longitudinal grooves and said extension thereof, and concrete filling said grooves and extensions to embed said horizontal rods therein.
 8. The combination according to claim 1, comprising also a first steel member embedded in at least one of said shelves and ledges and projecting upwardly from the upper surface thereof, and a second steel member embedded in the overlying part of said structure and resting upon the upper surface of said first steel member, thereby forming a clearance between said upper surface and the opposing surface of said overlying part, said upward projection of the first steel member determining the level of said overlying part.
 9. The combination according to claim 8, in which said clearance forms part of a continuous passage extending from the top of said overlying part to the bottom of said shelf or ledge, the combination comprising also cement filling said passage to form a joint. 